Hurricane Isaac made landfall this evening in southeastern Louisiana, with winds of 80 mph that spread out over an area 200 miles wide.

It was a Category 1 hurricane as it came ashore, and the National Hurricane Center warned of "strong winds and a dangerous storm surge occurring along the northern Gulf Coast."

The storm threatened to drop more than a foot of rain -- up to 20 inches in some areas -- from Biloxi, Miss., to New Orleans. The hurricane center said a storm surge -- the bulge of water that a storm pushes ahead of itself -- of 8.8 feet had been measured at Shell Beach, La.

Isaac, a massive and slow-moving storm, reached the coastline just a day short of the seventh anniversary of Hurricane Katrina, which devastated New Orleans in 2005. New Orleans Mayor Mitch Landrieu said Isaac's path is similar to Katrina's and the anniversary has created "a high level of anxiety."

"We don't expect a Katrina-like event, but remember there are things about a Category 1 storm that can kill you," Landrieu said. He urged people to avoid streets likely to flood.

"One of the things that's concerning about this storm is most of its major activity is occurring at night, which makes it a little more difficult to respond to," Landrieu said.

Usually boisterous New Orleans was a ghost town as tourists and locals heeded warnings and either left town or hunkered down in boarded-up buildings.

Rick Knabb, director of the National Hurricane Center in Miami, said it wasn't so much Isaac's strength as the speed at which it was moving that should concern the people living in its path.

"The models show [Isaac's] forward speed slowing down, and that's not good," Knabb said. "When a large system moves slowly, that means a lot of rainfall."

That was a worry that the New Orleans mayor echoed today as the storm approached.

"The thing that concerns us about this storm is that the fact that is it going so slow, slowly and that it could hover of the city for a long period of time," Landrieu said.

President Obama addressed the nation this morning, saying that the Federal Emergency Management Agency has been on the ground for more than a week working with officials in areas that could be affected.

"I want to encourage all residents of the Gulf Coast to listen to your local officials, and follow their directions, including if they tell you to evacuate," Obama said. "We're dealing with a big storm, and there could be significant flooding and other damage across a large area.

"Now is not the time to tempt fate. Now is not the time to dismiss official warnings. You need to take this seriously," he added.

In advance of the storm, Louisiana set up shelters and stockpiled more than a million packaged meals, 1.4 million bottles of water and 17,000 tarps.

Since the levees failed in Katrina seven years ago, more than $14 billion has been spent on the 133 miles of floodwalls, spillways, gates and pumps surrounding New Orleans.

"There is no evidence of any over-topping, whatsoever, we expect that the levees are going to hold," Landrieu said.

While officials say the city is more prepared now than it was in 2005, it's still taking no chances when it comes to evacuations.